Gday mate, it seems to me that you have a problem with your floats in the bottom part of your carbie, if you take the carby off you will see two screws on the botom which hold on the float bowl. Unscrew these and take the bowl off , be sure to watch for any parts and where they came from, if you have never been inside a carb before.
Notice the floats ? it seems likely that they are just getting jammed or need a slight adjustment, thoroughly clean out the float area with fuel and a compressor to blow out any caught debri.
After this, check to see that the floats arent damaged and that they are sitting level, all it takes is a slight bend of the float arm for adjustment, work it out until she seems right mate.....good luck..........if you have access to a manual for the bike it will all be covered in there......
Oh and nice bike........I too ride a 91 200F and love it to death, anyways........... :ride: :blah: :blah: have fun.